Hitachi Metals, Ltd.

Proterial, Ltd.

Kiyoshi Furushima

Masatsugu Uchida

Shunji Matsumoto

Ryota Honda

Kiyoshi Hayashi

Takashi Honda

Hideshige Matsuo

Takayuki Segawa

Kenji Date

Ryosaku Nawata

Itsuo Korenaga

Shingo Nogami

Toshinori Yashiro

Toshio Okitsu

Seiji Oyama

Takuya Osue

Kazunori Haratoh

A cylinder for a molding machine comprising a HIP-sintered lining layer on an inner surface of a cylindrical steel body, the lining layer comprising 38-70% by volume of tungsten carbide particles having a median diameter dof 1-7 &#x3bc;m and a matrix composed of an Ni-based alloy, and the maximum length of the matrix in an arbitrary cross section being 12 &#x3bc;m or less.

Cylinder for molding machine, and its production method

A molding machine cylinder comprising a lining layer having a structure comprising 20-50% by area of tungsten carbide particles and 1-10% by area of tungsten-based metal carboboride particles in a nickel-based alloy matrix, and containing 1-7.5% by mass of Fe, can be produced by a centrifugal casting method comprising a first step of heating at higher than 1140&#xb0; C. and lower than 1200&#xb0; C., and a second step of heating at 1080-1140&#xb0; C. after melting the raw material powder.

Molding machine cylinder and its production method

A centrifugally cast composite roll comprising an outer layer having a composition comprising by mass 2.5-9% of C, 0.1-3.5% of Si, 0.1-3.5% of Mn, and 11-40% of V, the balance being Fe and inevitable impurities; an intermediate layer made of a high-speed steel alloy, which is formed inside the outer layer; and an inner layer made of cast iron or steel, which is formed inside the intermediate layer.

Centrifugally cast composit roll

A method for producing an outer layer for a roll having a structure having MC carbide dispersed at an area ratio of 20-60%, comprising the steps of (1) centrifugally casting a melt having a composition comprising, by mass, 2.2-6.0% of C, 0.1-3.5% of Si, 0.1-3.5% of Mn, and 8-22% of V, the balance being Fe and inevitable impurity elements, to produce a cylindrical body comprising an inner layer having concentration MC carbide, an MC-carbide-poor outer layer, and a concentration gradient layer between the inner layer and the outer layer, in which the area ratio of MC carbide changes, and (2) cutting the cylindrical body to a depth at which the area ratio of MC carbide is 20% or more.

Centrifugally cast external layer for rolling roll and method for manufacture thereof

The compound roll comprising a shell portion made of a hard cast iron having excellent wear resistance and resistance to surface roughening and a core portion made of a tough cast iron or cast steel, the cast iron of the shell portion having a composition consisting essentially, by weight ratio, of 2.5-3.5% of C, 0.5-1.5% of Si, 0.5-1.5% of Mn, 0.1% or less of P, 0.05% or less of S, 3.0-5.0% of Ni, 1.0-2.5% of Cr, 0.1-1.5% of Mo and balance Fe and inevitable impurities, an average diameter of primary precipitated particles constituting a matrix of the metal structure of the shell portion being 80 .mu.m or less in a range from a surface to a depth of 50 mm when determined by an image analysis method on the primary precipitated particles having diameters exceeding 30 .mu.m, and the primary precipitated particles satisfying the formula: m.sub.2 .ltoreq.1.2 m.sub.1, wherein m.sub.1 is an average diameter of the primary precipitated particles at the surface of the shell portion, and m.sub.2 is an average diameter of the primary precipitated particles at the depth of 50 mm, is produced by supplying a melt for the shell portion at a temperature T satisfying the formula: Tc-20.degree. C..ltoreq.T.ltoreq.Tc+70.degree. C., wherein Tc is a primary crystal-forming temperature of the melt for the shell portion, to a hollow cylindrical mold rotatable around its longitudinal axis, at such a speed that an average shell portion-forming speed in the mold is 2-40 mm/min.

Method of producing a compound roll

Die casting cylinder

A protective tube for a thermocouple for measuring the temperature of molten metal, comprising two layers, an inner layer being made of a silicon nitride or sialon ceramic having a bending strength of 50 kg/mm.sup.2 or more, a density of 90% or more based on a theoretical density and a thermal shock temperature .DELTA.T of 400.degree. C. or more, and an outer layer being formed on the silicon nitride or sialon ceramic and containing BN and SiO.sub.2. The silicon nitride of sialon ceramic comprises 70 weight % or more of Si.sub.3 N.sub.4 having 65 weight % or more of an .alpha.-phase content, 20 weight % or less of one or more oxides of elements of Group IIIa of the Periodic Table, 20 weight % or less of Al.sub.2 O.sub.3, and optionally 15 weight % or less of AlN or AlN solid solution, and the outer layer is composed mainly of BN-SiO.sub.2 -Al.sub.2 O.sub.3 -Y.sub.2 O.sub.3. This protective tube is produced by coating ceramic powder comprising BN and SiO.sub.2 before sintering. This protective tube can enjoy an extremely long life.

Protective tube for thermocouple and method of producing same

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Kitakyusyu, Japan

Kiyoshi Furushima